No way to remove/delete Topics from API or UI

The Topics functionality and API new in 14.5 doesn't provide a way to remove topics. For example, if there are any typos or abuse in the topics feature, there is no way to clean it up.

Via @strausmann 's comment from #345645 (closed):

how can i remove a topic and empty topics and empty topics should not be displayed in the overview. Additionally, identical topics that were only written differently should be connected to each other. Example:

php, PHP, Php => merge PHP.